Starch trays of rectangular shape, usually of hardwood timber, are employed in the confectionery trade for the manufacture of sweets. The trays are substantially filled with starch powder, which is packed flat and then stamped with a multiple head moulding tool to form impressions in the layer of starch. These impressions are filled with a prescribed quantity of fluid sweet mixture, which is caused to solidify by air drying or oven drying. The tray is then tipped out, the sweets for packaging and the starch powder for recycling. During drying of the sweet mixture, the trays are stacked one on top of the other. The stacking requirement may be for as many as forty trays, and the achievement of a stable stack is essential. Most desirably, the trays in the stack should be aligned with only very limited freedom for relative sliding movement of one tray relative to another both parallel to and at right angles to the length of the trays. However, a construction of tray satisfying these requirements is not easily achieved, because in use starch powder settles on all upwardly facing surfaces around the periphery of the tray. While powder on the flat top surface of the upstanding peripheral wall is readily brushed off, the act of brushing is only likely to increase the accumulation of powder in any closed or partly closed recesses which may be provided to assist in the achievement of aligned stacking with minimal relative sliding movement between the trays in the stack. Any such accumulation of powder will lead to instability or lopsidedness of the stack, and the instability will tend to be cumulative as the height of the stack is increased.
It is an object of this invention to provide a starch tray which enables satisfactory stable aligned stacking to be achieved, in accordance with the above-described requirement.